We do not have a rational drug policy. There are potent and dangerous drugs that are socially accepted because hey, we’ve always drunk alcohol and smoked cigarettes, while there are milder, far less dangerous drugs that are damned because they’re new and unfamiliar. And so we throw people in prison for long jail terms if they are caught with some marijuana, while people can go out every weekend and drink themselves into an abusive, obnoxious state, and we just tell them they’re cool.

Humans indulge in activities that alter both the content and the experience of their own consciousness. Drugs are a means for achieving a number of particular, often recreational, changes in conscious experience. However, drugs are also a large contributor to, and facilitator of, human suffering and health problems. The best health advice anyone can give to most people most of the time regarding recreational drug use is this: “Do not use drugs”. Many people however, including me, do not find this advice particularly attractive, or even sensible. Assuming that a person wants to enjoy the mind-altering effects of psychoactive substances, two questions follows: which drugs are dangerous to use? And, more importantly – how can one know which drugs are more dangerous than others? The answer to both questions, of course, can be found through the illuminating lens of the scientific method.

David Nutt and his colleagues have studied the relative harm of drugs. In one of Nutt’s studies that were published in the lancet, members of the British Independent Scientific Committee on Drugs was asked to rate 20 drugs on 16 criteria such as drug-specific damage, mortality, dependence and international damage. Drugs were scored on a 100-point scale. Here is a display of the weighted scores:

In the diagram above both individual and societal factors are considered. It may come to a surprise to many readers that LSD and ecstasy are one of the least dangerous drugs. Notice also that Alcohol is the highest rated dangerous drug and that tobacco is on seventh place just below Cocaine (Both alcohol and tobacco are not even considered a drug by many people, including, sadly, politicians). However, heroin, crack and metamfetamine tops the list for the most dangerous drugs when only individual factors are considered, alcohol then dropping down to a fourth place amongst the most dangerous drugs. So, even when the obvious societal effects due to the widespread use of alcohol are not considered (alcohol rates very high, unsurprisingly, on “family adversities” and “environmental damage”) it still is the fourth most dangerous drug. Yes, that’s right. Alcohol nearly receives the bronze-medal for danger to individuals.

The particular type of neurotransmitters that a drug affects in the brain has a huge impact on the harms the drug can contribute to. A major similarity between the drugs that tops the list above is that these drugs, in addition to other areas in the brain (click here for a discussion), directly affect the dopaminergic “reward system” in the midbrain. This area has been shaped and “designed” by millions of years of natural selection in mammals to reward for adaptive behavior such as sex and the intake of nutritious food. When they are artificially stimulated by drugs such as heroin and crack cocaine they have adverse consequences for addiction and health (that is the reason why drugs such as nicotine and heroin have the characteristic addictive effects). Drugs at the bottom of the list, such as MDMA (ecstasy), mushrooms and LSD stimulate mainly serotonergic neurons (several places in the brain), and does not directly stimulate the mesolimbic reward systems (which is why they are not addictive).

The many myths and popular beliefs surrounding psychoactive substances and their harms are perpetuated through the popular media. An empirical observation of this phenomenon was provided by Alasdair Forsyth in 2001. He compared the official statistics on drug deaths in Scotland to the drug-deaths reported in the Scottish newspapers. His results are somewhat astounding: a huge proportion of deaths caused by recreational drugs were reported, whereas deaths caused by pharmaceutical drugs were vastly underreported. For example, 26 of 28 deaths were MDMA (ecstasy) was a possible contributor to death was reported, whereas just one in every 256 deaths caused by aspirin and one in 50 deaths caused by paracetamol were reported. This clearly gives a biased representation of the relative harm of drugs, particularly ecstasy, which, as is reported in the diagram above, is not at all that dangerous.

Cannabis is, relative to other drugs, one of the less harmful drugs. This may be hard to believe for some, because cannabis is one of the drugs that are highly politicized – misinformed policies and governments contribute a great deal to the wrongful assumptions and belief-patterns held in many societies. A common worry is that cannabis causes psychotic disorders and/or schizophrenia or that it is a “gateway drug” which leads to the abuse of more dangerous drugs. Both hypotheses have been put to the test:

There is indeed a correlational pattern between cannabis use and the development of psychosis (individuals with schizophrenic disorders are four times more likely to have smoked marihuana than the general population). This could mean, but not necessarily, that cannabis use causes psychosis – but correlation, importantly, does not imply causation. A Danish study found that individuals who were treated for post-marihuana smoking psychotic episodes had the same likelihood of having first-degree family members (mothers, siblings etc.) with schizophrenia as individuals who had been treated for schizophrenia itself (non-cannabis smokers). Those results suggest that cannabis can induce schizophrenia/psychosis in individuals that are genetically predisposed for developing the disorder, regardless of cannabis use. Arendt, one of the authors of the study, has commented that “these people would have developed schizophrenia whether or not they used cannabis”.

The gateway hypothesis is more controversial in the scientific literature. However, research on the gateway-hypothesis often suffers from the same flaws: a correlation between cannabis use and other drugs can be found, a possible causal relationship needs further scientific inquiry. Once again, the logical pitfall of the Post hoc ergo propter hoc fallacy must be avoided. Many cannabis smokers drank milk before they started smoking pot. Is there a causal effect? The reason why there is a relationship between cannabis smoking and other drugs (or indeed between the uses of several drugs in general) can be a result of genetic risk factors that contributes to increased risks for drug abuse in particular individuals. Humans with a stronger activation pattern in the brains reward system during intake of a drug have a susceptibility to drug abuse in general (interestingly, individuals that have a weak or absent activation in their dopaminergic reward systems when injected with alcohol are much more likely to be abstainers). This is why, most likely, that there is a correlation between cannabis use and other drugs, not because it is a “gateway” to the usage of several drugs.

It is important not to confuse illegality with dangerousness. The reasons why drugs are assigned particular legal statuses are mainly cultural and political in nature, not scientific. Now, does it not make sense, given the scientific understanding of relative drug harm, to correspond a drug’s legal and social status with the harm one can prescribe to it? It is of a great moral concern if risks of harm on particular psychoactive substances and their legal status remain unrelated. A study comparing cannabis use in Amsterdam (where cannabis is decriminalized) and San Francisco (criminalized) found no evidence that criminalization of cannabis reduces use, or that decriminalization increases use. In other words, cannabis legal status seems to be fairly unrelated to the amount, and to which extent, people get high. Clearly, a legal system that regulates and taxes cannabis use (like alcohol), rather than imprisons and criminalizes its users, which by the way, uses ridiculous amounts of tax-payers money, makes more sense.

Imagine if your child were to try a mind-altering drug. Would you rather have your child use a drug which, compared with other drugs, are less likely to cause harm? If you are a person with a decently functioning moral-reasoning device, “yes” is probably your answer. Harm is not the only relevant factor either. Some drugs (e.g. Psilocybin, LSD, and MDMA) can produce insightful and interesting effects on the mind that expands, rather than numb down, one’s own conscious experience. Sam Harris puts it nicely:

“Needless to say, if I knew my daughter would eventually develop a fondness for methamphetamine or crack cocaine, I might never sleep again. But if she does not try a psychedelic like psilocybin or LSD at least once in her adult life, I will worry that she may have missed one of the most important rites of passage a human being can experience.”

Wouldn’t it be interesting if we had laws and penalties that were actually informed by science, rather than fear and naivete?

The aim of science is to make difficult things understandable in a simpler way. The aim of poetry is to state simple things in an incomprehensible way.
Paul Dirac

“I do not feel obliged to believe that the same God who has endowed us with sense, reason and intellect, has intended us to forego their use”. Galileo (1584-1682).

“Facts do not cease to exist because they are ignored. ”
Aldous Huxley.

“It is the nature of human species to reject what is true but unpleasant but to embrace what is obviously false but comforting.” H.L. Mencken.

Eric Sevareid’s Law: “The chief source of problems is solutions”.

“What is lacking is not sufficient knowledge of the solution, but universal consciousness of the gravity of the problem and the education of the billions who are its victims.“
Dr. Martin Luther King Jr.

The greatest shortcoming of human race is our inability to understand the simple arithmetic. Albert Bartlett

Thinking is very upsetting, it tells us things we should rather not know.

“That which can be asserted without evidence, can be dismissed without evidence.” ― Christopher Hitchens

Ignorance is nothing to be ashamed of, and thinking and learning cures the problem of ignorance.

In contrast stupidity is forever, and being stupid implies wanting to remain ignorant. Lawrence B. Crowell

The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts.
— Bertrand Russell

The majority of people are idiots, and because of this the few can control them. LC

For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.
Carl Sagan

Where a drunken person drinks in order to be happy, who can deny that such a person is happy when drunk? But the happiness can become a crutch and can be unhealthy in the long run. The happiness is only apparent and not real. Leyton M

If you look at the work of the ethologists (people who study animal behaviour) the most striking result to me is that all species develop behaviour patterns appropriate to their life styles and evolutionary niches in which they evolve.

I would suppose that this applies also to that degraded animal species, Homo sapiens. Sydney

“To most of us nothing is so invisible as an unpleasant truth. Though it is held before our eyes, pushed under our noses, rammed down our throats – we know it not.” Eric Hoffer

At the heart of science is an essential balance between two seemingly contradictory attitudes:
- an openness to new ideas, no matter how bizarre or counterintuitive, and
- the most ruthlessly skeptical scrutiny of all ideas, old and new.
This is how deep truths are winnowed from deep nonsense.
Carl Sagan

“Anyone who thinks that an economy can be expanded forever, within the confines of a finite planet, is either a madman or an economist”. ~ Kenneth Boulding.

We have got rid of the fetish of the divine right of kings, and that slavery is of divine origin and outhority. But the divine right of property has taken its place. The tendency plainly is towards…’a government of the rich, by the rich and for the rich’.
Rutherford Birchard Hayes, US Prezident 1822-1893.

While one person hesitates because he feels inferior, the other is busy making mistakes and becoming superior. –
Henry C. Link

Experience is that marvelous thing that enables you to recognize a mistake when you make it again. – Franklin P. Jones

To avoid situations in which you might make mistakes may be the biggest mistake of all. – Peter McWilliams

Mistakes are part of the dues one pays for a full life. –
Sophia Loren

A life spent making mistakes is not only more honorable, but more useful than a life spent doing nothing. –
George Bernard Shaw

A man’s mistakes are his portals of discovery. – James Joyce

Experience is the name everyone gives to their mistakes.
– Oscar Wilde

Mistakes, obviously, show us what needs improving. Without mistakes, how would we know what we had to work on?
– Peter McWilliams

Creativity is allowing yourself to make mistakes. Art is knowing which ones to keep. – Scott Adams

Success seems to be connected with action. Successful people keep moving. They make mistakes, but they don’t quit.
– Conrad Hilton

Anyone who has never made a mistake has never tried anything new. – Albert Einstein

All men make mistakes, but only wise men learn from their mistakes. – Winston Churchill

Take chances, make mistakes. That’s how you grow. Pain nourishes your courage. You have to fail in order to practice being brave.
– Mary Tyler Moore

There are no mistakes. The events we bring upon ourselves, no matter how unpleasant, are necessary in order to learn what we need to learn; whatever steps we take, they’re necessary to reach the places we’ve chosen to go. – Richard Bach

The only real mistake is the one from which we learn nothing.
– John Powell

If you have made mistakes, there is always another chance for you. You may have a fresh start any moment you choose, for this thing we call ‘failure’ is not the falling down, but the staying down. – Mary Pickford

Fall down seven times, stand up eight. – Chinese proverb

Without music, life would be a mistake. – Friedrich Nietzsche

The only man who never makes a mistake is the man who never does anything. – Theodore Roosevelt

Never interrupt your enemy when he is making a mistake. Napoleon Bonaparte

Never attribute to malice what can be explained by stupidity.

Evolution is almost universally accepted among those who understand it, almost universally rejected by those who don't. Richard Dawkins

Indeed, I tremble for my planet, when I reflect that Nature is inflexible: that her response to our abuse cannot sleep forever.
Thomas Jefferson

If we don’t halt population growth with justice and compassion, it will be done for us by nature, brutally and without pity — and we will leave a ravaged world.
Dr. Henry W. Kendall, Nobel Laureate

No one in their right mind would let a first-century dentist fill their children’s teeth. Why, then, do we allow first-century theologians to fill our children’s minds?” Michael Dowd

Older people can see the injustice with more understanding and compassion. Laura Carstensen

Excessive Privilege should never be due merely to the luck of birth, nor should it ever be excessive even when earned.
Bob Zannelli

Humanity today is like a waking dreamer, caught between the fantasies of sleep and the chaos of the real world. We have created Star Wars civilization, with stone age emotions, medieval institutions and godlike technology. We are terribly confused by the mere fact of our existence, and a danger to ourselves and to the rest of life.
Edward Osborn Wilson

If thou wilt make a man happy, add not unto his riches but take away from his desires. Epicurus

Turn every challenge into an opportunity, because opportunities open up for the prepared.

The Law, in its majestic equality, forbids the rich, as well as the poor, to sleep under the bridges, to beg in the streets, and to steal bread. Anatole France

Psychopath is someone who wants to do whatever he wants without concern for the consequences for others, and who strongly resents any restraint. kerry

Philosophy of science is about as useful to scientists as ornithology is to birds. Richard Feynman

More discoveries come from finding out that you're wrong than from finding out that you're right. Ian Linnell

"The old scientific ideal of episteme - of absolutely certain, demonstrable knowledge - has proved to be an idol. The demand for scientific objectivity makes it inevitable that every scientific statement must remain tentative for ever. It may indeed be corroborated, but every corroboration is relative to other statements which, again, are tentative. Only in our subjective experiences of conviction, in our subjective faith, can we be 'absolutely certain.'"
- The Logic of Scientific Discovery, 1934, 1959

Faith is believing what you know isn't true.
Mark Twain

If you can't explain it simply, you don't understand it well enough."
A. Einstein

We can easily forgive a child who is afraid of the dark;
the real tragedy of life is when men are afraid of the light.
-- Plato

"You can never cross the ocean until you have the courage to lose sight of the shore." Christopher Columbus

"We are a way for the Universe to know itself". Carl Sagan

"Labor is prior to, and independent of, capital. Capital is only the fruit of labor, and could never have existed if labor had not first existed. Labor is the superior of capital, and deserves much higher consideration." --Abraham Lincoln

The most honorable way a scientist can make his contribution to human progress is to distribute knowledge. For free. I.V.

First love is a kind of vaccination which saves a man from catching the complaint the second time. - Honore de Balzac

College is a place where professor's lecture notes go straight to the student's lecture notes, without passing through the brains of either. Mark Twain

The mind is not a vessel that needs filling, but wood that needs igniting. Plutarch

To say that God did it is not to explain anything, but simply to offer an excuse for not having an explanation. (Plato, Cratylus)

The price of knowledge is eternal skepticism. Justen Robertson

If you can't measure it, it doesn't exist.
If you can't reproduce it, you don't understand it.

Power derives from force or the threat of force. Authority is the likelihood that a command, once given, will be obeyed.
Max Weber

If you break the laws of logic or probability theory you decrease your chances of arriving at true beliefs, and if you break the laws of decision theory then you decrease your chances of achieving your goals. Luke Muehlhauser

Give a child religion first, and she may find it hard to shake even when she encounters science.
Give a child science first, and when she discovers religion it will look silly. Luke Muehlhauser

We can easily forgive a child who is afraid of the dark;
the real tragedy of life is when men are afraid of the light.
-- Plato

"I see in the near future a crisis approaching that unnerves me and causes me to tremble for the safety of my country. . . . corporations have been enthroned and an era of corruption in high places will follow, and the money power of the country will endeavor to prolong its reign by working upon the prejudices of the people until all wealth is aggregated in a few hands and the Republic is destroyed."
-- U.S. President Abraham Lincoln, Nov. 21, 1864

"Human beings function better if they are deceived by their genes into thinking that there is a disinterested objective morality binding upon them, which all should obey."
--E. O. Wilson

"My propositions serve as elucidations in the following way: anyone who understands me eventually recognizes them as nonsensical."
--Wittgenstein

"Act only on that maxim by which you can at the same time will that it should become a universal law."
--Kant

"Man when perfected is the best of animals, but when separated from law and justice he is the worst of all."
--Aristotle

"I do not fear death, in view of the fact that I had been dead for billions and billions of years before I was born, and had not suffered the slightest inconvenience from it."'
--- Mark Twain

Not only will men of science have to grapple with the sciences that deal with man, but -- and this is a far more difficult matter -- they will have to persuade the world to listen to what they have discovered. If they cannot succeed in this difficult enterprise, man will destroy himself by his halfway cleverness.
~ Bertrand Russell, 1951

“The art of progress is to preserve order amid change and to preserve change amid order.”
— Alfred North Whitehead

For any belief, it is always possible to come up with a seemingly unlimited amount of supporting evidence.
David P. Barash

Science deals with facts discovered by observation and experimentation. Philosophy deals with beliefs derived by inference from facts.

We owe respect to the living. To the dead we owe only truth.
Voltaire

Dreams are illustrations from the book your soul is writing about you. Mascha Normann

You are what you do, not what you say.

"Of all things, good sense is the most fairly distributed: everyone thinks he is so well supplied with it that even those who are the hardest to satisfy in every other respect never desire more of it than they already have."
René Descartes, Discourse on Method, 1637

If the writing is honest it cannot be separated from the man who wrote it. Tennessee Williams

You don’t really understand how something works until you can reproduce it yourself.

“The greatest obstacle to discovery is not ignorance-it is the illusion of knowledge.” -Daniel Boorstin

"...be careful what you wish for, you might get it..."

If there is any inconsistency in a set of axioms then every statement can be proved (and disproved), and nothing of any value remains. Chaitin, G.

Sorrow is how we learn to love. Your heart isn't breaking. It hurts because it's getting larger. The larger it gets, the more love it holds. Rita Mae Brown

A self is not something static, tied up in a pretty parcel and handed to the child, finished and complete. A self is always becoming. Madeleine L'Engle

People demand freedom of speech as a compensation for the freedom of thougt which they seldom use. Soren Kirkegaard

Most of the important things in the world have been accomplished by people who have kept on trying when there seemed to be no hope at all. Dale Carnegie

Education is not the learning of facts, but the traning of the mind to think. Albert Einstein.

To create, one must question everything. Eileen Gray.

Time is a great teacher, but unfortunately it kills all its pupils.
Louis Hector Berlioz.

Remember: the time you feel lonely is the time you most need to be by yourself. Life's cruelest irony. Douglas Coupland

Love is lak de sea. It’s uh movin’ thing, but still and all, it takes its shape from de shore it meets, and it’s different with every shore. Zora Neale Hurston

If the real world were a book, it would never find a publisher. Overlong, detailed to the point of distraction - and ultimately, without a major resolution. Jasper Fforde

Do not regret growing older. It is a privilege denied to many.

The time will come when, with elation, you will greet yourself arriving
at your own door, in your own mirror, and each will smile at the other’s welcome. Derek Walcott

Only a rule of skin in the game, that is, direct harm from one's errors, can puncture the game aspect of research and establish some form of contact with reality.
Nassim Nicholas Taleb, Distinguished Professor of Risk Engineering, NYU-Poly

For each of us comes a time when we must be more than what we are. Lloyd Alexander

There are in nature neither rewards nor punishments - there are only consequences.
Robert G. Ingersoll

"The fact that a believer is happier than a skeptic is no more to the point than the fact that a drunken man is happier than a sober one." ~ GEORGE BERNARD SHAW

Nobody ever figures out what life is all about, and it doesn't matter. Explore the world. Nearly everything is really interesting if you go into it deeply enough. Richard P. Feynman

Laws are the spider's webs which, if anything small falls into them they ensnare it, but large things break through and escape. -Solon

Worry never robs tomorrow of its sorrow, but only saps today of its strength. A.J. Cronin

Keep your eyes on the stars, and your feet on the ground. ” — Theodore Roosevelt

‘One death is a tragedy, a million a statistic.’ Josef Stalin

I have just realized that the stakes are myself.
I have no other ransom money, nothing to break or barter but my life. Diane di Prima

We live at a time when emotions and feelings count more than truth, and there is a vast ignorance of science. James Lovelock

Champagne, if you are seeking the truth, is better than a lie detector. Graham Greene

By sticking your head in the sand and refusing to acknowledge the problem, you are part of it.
Anne O'Reily

Peace cannot be kept by force.
It can only be achieved through understanding.
Albert Einstein

To see what is in front of one's nose requires a constant struggle. G. Orwell.

Anyone can be a barbarian; it requires a terrible effort to remain a civilized man. Leonard Woolf

When we killed--or exiled--God, we also killed ourselves.... No God, no afterlife, no us. We were right to kill Him, of course, this long-standing imaginary friend of ours. And we weren't going to get an afterlife anyway. But we sawed off the branch we were sitting on. And the view from there, from that height--even if it was only an illusion of a view--wasn't so bad.
Julian Barnes

All people are not people without other people.

We are a way of the cosmos to know itself.
Carl Sagan

It is easier to point the finger of blame at others than it is to find and implement solutions.
William Benson

Whatever it is you're seeking won't come in the form you're expecting. Haruki Murakami